It wasn't the emails...

[pnwmom]

14. The Russians used the Sanders campaign to divide Democrats.

And because Sanders continued to campaign all the way up to the convention, the party was not yet united and the door was open to Russia's timely interference.

https://www.vox.com/policy-and-politics/2017/7/11/15952666/russia-dnc-hacks-timing

Russians timed and framed this well

Had the DNC emails come out earlier, they would, of course, have been an issue in the 2016 primary campaign. And while it’s conceivable that they would have helped Sanders win the nomination, it’s more likely that he still would have lost. Either way, they would have been part of the campaign, and the convention would have been an opportune moment to put the disagreement in the past.

By raising the issue after the primary was over but before the party had come together in a big show of unity, the emails were released at a perfect moment for making trouble.

And at the time they were released, WikiLeaks’ primary brand in the West was as a left-wing muckraking site — the kind of place to which Sanders supporters might turn for a critical glimpse at the political establishment. Russia’s state-owned English-language media simultaneously offered a steady diet of overheated takes about a rigged primary that were framed as left-wing attacks on Clinton.

Clinton’s campaign team, to their credit, had this plan nailed correctly at the time. They argued that the real story the media should be focused on was a coordinated Russian government effort to help Donald Trump win the election. Had the media seen it that way at the time, the revelations would of course have been covered differently. And, critically, had Sanders and his supporters seen it that way at the time, they likely would have reacted differently. But instead, the timing and framing were just right for Sanders backers to see the revelations as aligned with their own campaign against the political establishment.

SNIP

But it’s true that even as Trump performed historically badly with young voters, Clinton was hurt by relatively low turnout among under-30s and a relatively high level of defection to third-party candidates. To attribute all of her problems with mobilizing Trump-hating young people to the hack would, of course, be going too far. But it’s fair to say that she lost in large part due to a failure of the unity efforts with Sanders, efforts that were sabotaged by a very well-timed and very well-framed release of stolen DNC emails.